The Question

SuperUser reader Naughty.Coder wants to know:

Packets travel through internetworks, and take many routes through internet routers. On each route that forwards traffic to another until reaching the ultimate destination, what stops them from viewing the packets they receive/forward?

Now, we’re not saying there’s a correlation between his username and his curiosity about people sniffing his packets, but this is definitely our favorite SuperUser username/question combination to date.

The Answer

SuperUser Kwaio offers some insight:

Short answer : you can’t prevent them from sniffing your traffic, but you can make it meaningless for them by using encryption.

For example, if you use HTTPS instead of HTTP, the content of the webpages you fetch will not be readable from those routers.

But remember that they can still save the encrypted packets and try to decrypt them. Decryption is never about “can or can’t”, it’s about “How much time does it take”. So use ciphers and key lengths suitable for the degree of privacy you need, and the “expiration time” of the data you want to “hide”. (meaning if you don’t care if someone gets it a week after the transmission, use a strong protocol. If it’s an hour, you can lower the key length)

Jason Fitzpatrick is warranty-voiding DIYer and all around geek. When he's not documenting mods and hacks he's doing his best to make sure a generation of college students graduate knowing they should put their pants on one leg at a time and go on to greatness, just like Bruce Dickinson. You can follow him on Google+ if you'd like.